Actuator with dynamic characteristic and a four section VCM coil and disk drive having the same

1. An actuator of a disk drive to move a read/write head, for recording and reproducing data, to a predetermined position on a disk, the actuator comprising: an actuator pivot installed on a base member of the disk drive; a swing arm rotatably coupled to the actuator pivot and having a suspension supporting the head and formed at a leading end portion of the swing arm; a coil support portion provided at a rear end portion of the swing arm; a VCM coil coupled to the coil support portion and having four sections having respective particular directions; and magnets arranged to face the VCM coil and having four poles respectively corresponding to the four sections of the VCM coil, wherein, when current is applied to the VCM coil, directions of the current in the four sections of the VCM coil are different from one another, and wherein, assuming that a lengthwise direction of the actuator is a direction X and a widthwise direction of the actuator is a direction Y, first and second sections of the four sections of the VCM coil are disposed, away from the actuator pivot, on opposite sides with respect to an X direction center line and inclined to be symmetrical with each other with respect to the X direction center line, and third and fourth sections of the VCM coil are disposed, close to the actuator pivot, on opposite sides with respect to the X direction center line and inclined to be symmetrical with each other with respect to the X direction center line.

2. The actuator as claimed in claim 1 , wherein the VCM coil has a substantially hexagonal shape and the first, second, third, and fourth sections correspond to four sides of the hexagonal shape, except for two sides parallel to the direction Y.

3. The actuator as claimed in claim 1 , wherein the directions of forces acting on the first, second, third, and fourth sections are different from one another.

4. The actuator as claimed in claim 1 , wherein the four poles of the magnets are magnetized such that neighboring poles have opposite polarities.

5. The actuator as claimed in claim 1 , wherein the magnets comprise an upper magnet disposed above the VCM coil and a lower magnet disposed under the VCM coil and four poles of the upper magnet and four poles of the lower magnet are magnetized such that poles facing each other have opposite polarities.

6. An actuator of a disk drive to move a read/write head, for recording and reproducing data, to a predetermined position on a disk, the actuator comprising: an actuator pivot installed on a base member of the disk drive; a swing arm rotatably coupled to the actuator pivot and having a suspension supporting the head and formed at a leading end portion of the swing arm; a coil support portion provided at a rear end portion of the swing arm; a VCM coil coupled to the coil support portion and having four sections having respective particular directions; and magnets arranged to face the VCM coil and having four poles respectively corresponding to the four sections of the VCM coil, wherein, when current is applied to the VCM coil, directions of the current in the four sections of the VCM coil are different from one another, and wherein, assuming that a lengthwise direction of the actuator is a direction X and a widthwise direction of the actuator is a direction Y, first and second sections of the four sections of the VCM coil are disposed, away from the actuator pivot, on opposite sides with respect to an X direction center line and inclined to be symmetrical with each other with respect to the X direction center line, and third and fourth sections of the VCM coil are disposed, close to the actuator pivot, on opposite sides with respect to the X direction center line and parallel to the X direction center line.

7. The actuator as claimed in claim 6 , wherein the directions of forces acting on the first and second sections are different from each other while the directions of forces acting on the third and fourth sections are substantially identical.

8. A disk drive including a disk for storing data, a spindle motor to rotate the disk, and an actuator to move a read/write head, for recording and reproducing data, to a predetermined position on the disk, the actuator comprising: an actuator pivot installed on a base member of the disk drive; a swing arm rotatably coupled to the actuator pivot and having a suspension supporting the head and formed at a leading end portion of the swing arm; a coil support portion provided at a rear end portion of the swing arm; a VCM coil coupled to the coil support portion and having four sections having respective particular directions; and a magnet arranged to face the VCM coil and having four poles respectively corresponding to the four sections of the VCM coil, wherein, when current is applied to the VCM coil, directions of the current in the four sections of the VCM coil are different from one another, wherein, assuming that a lengthwise direction of the actuator is a direction X and a widthwise direction of the actuator is a direction Y, first and second sections of the four sections of the VCM coil are disposed, away from the actuator pivot, on opposite sides with respect to an X direction center line and inclined to be symmetrical with each other with respect to the X direction center line, and third and fourth sections of the VCM coil are disposed, close to the actuator pivot, on opposite sides with respect to the X direction center line and inclined to be symmetrical with each other with respect to the X direction center line.

9. The disk drive as claimed in claim 8 , wherein the VCM coil has a substantially hexagonal shape and the first, second, third, and fourth sections correspond to four sides of the hexagonal shape, except for two sides parallel to the direction Y.

10. The disk drive as claimed in claim 8 , wherein the directions of forces acting on the first, second, third, and fourth sections are different from one another.

11. The disk drive as claimed in claim 8 , wherein the four poles of the magnets are magnetized such that neighboring poles have opposite polarities.

12. The disk drive as claimed in claim 8 , wherein the magnets comprise an upper magnet disposed above the VCM coil and a lower magnet disposed under the VCM coil and four poles of the upper magnet and four poles of the lower magnet are magnetized such that poles facing each other have opposite polarities.

13. A disk drive including a disk for storing data, a spindle motor to rotate the disk, and an actuator to move a read/write head, for recording and reproducing data, to a predetermined position on the disk, the actuator comprising: an actuator pivot installed on a base member of the disk drive; a swing arm rotatably coupled to the actuator pivot and having a suspension supporting the head and formed at a leading end portion of the swing arm; a coil support portion provided at a rear end portion of the swing arm; a VCM coil coupled to the coil support portion and having four sections having respective particular directions; and a magnet arranged to face the VCM coil and having four poles respectively corresponding to the four sections of the VCM coil, wherein, when current is applied to the VCM coil, directions of the current in the four sections of the VCM coil are different from one another, and wherein, assuming that a lengthwise direction of the actuator is a direction X and a widthwise direction of the actuator is a direction Y, first and second sections of the four sections of the VCM coil are disposed, away from the actuator pivot, on opposite sides with respect to an X direction center line and inclined to be symmetrical with each other with respect to the X direction center line, and third and fourth sections of the VCM coil are disposed, close to the actuator pivot, on opposite sides with respect to the X direction center line and parallel to the X direction center line.

14. The disk drive as claimed in claim 13 , wherein the directions of forces acting on the first and second sections are different from each other while the directions of forces acting on the third and fourth sections are substantially identical.